Raid 0+1

[Chris_PC]

For my New PC im thinking of a Raid 0+1 setup, using Western Digital wd2500ys "server class" drviers which come with 5 year warranty(Instead of 3)
dabs.com - Western Digital Caviar 250GB S300 16MB 7200RPM (WD2500YS)

I would have 4 drives in total.
What I would like to know, is how would I know if one of the drives has failed?
Also, are there any other, better options?
Im looking at the Raid 0 for speed, But my data needs to be backed up.

 

[Waphlez]

If one of the drives fail, both drives fail, or something like that.

 

[Chris_PC]

Thats for the raid 0 config, if one drive fails, you lose the data spread over two drives. Thats why Im planning on adding the Raid 1